Filler main

For propellant charges the insensitivity is also playing an increasingly important role. Since approximately 1970 propellant charges have been developed and used under the title LOVA (low-vulnerability ammunition). Under bullet impact, shaped charge impact or fire they respond with fire in the worst case scenario, but not in deflagration and definitely not in detonation. As energetic fillers mainly RDX... 

Fillers such as CaCOs, clay, etc. with average particle size in the range 01 to 100 nm may be defined as nanofillers. Unlike traditional fillers, mainly used for cost reduction, nanofillers are performance-enhancing fillers used in relatively small amounts (5 10%) in order to provide substantial improvements in physical and other properties. Nanosized particles (average diameter around 40 nm) form a very fine and homogeneous distributed system in polymer matrix. As compared to micron size filler particles the nanosized filler particles are able to occupy substantially greater number of sites in the polymer matrix. 

Filler Main mineral (crystalline phase) Chemical composition (simplistic formulae used for the silicates, see individual entries for details) Shape... 

Biocomposites are obtained by the incorporation of macro-fillers (mainly ligno-cellulose fibres) in a biopolymer matrix. One of the main advantages of... 

These are similar in chemical composition to the thermoplastic polyesters, but contain reactive unsaturated sites so that they can be cross-linked. Fillers, mainly calcium carbonate but also alumina trihydrate and tale, are added to increase the viscosity, strength, stiffness and impact resistance. The major thermoset applications for calcium carbonate are in cultured marble for sink units, counter tops, spas and bowling balls. 

Bulk Molding Compoimd, BMC, (Dough Molding Compound in Europe) is produced by first mixing pre-catalyzed liquid resin with fillers, mainly calcium carbonate and talc, in a heavy duty low speed sigma blade mixer. This is compression molded at 500 psi and 300 to 400°F. The resin most commonly used is unsaturated styrene-diluted polyester. Other BMC resins are alkyds, phenolics, urea, melamine, diallyl phthallate, silicones and epoxy. All are highly filled with calcium carbonate, talc, mica or alumina to improve mechanical properties and reduce shrinkage. 

Unfilled RIM polymers have low rigidity and high coefficients of thermal expansion, which is a problem when they are mated with metal parts. To overcome these defects fillers, mainly mica and wollastonite, are added to the polyol components by the molder to create RRIM. These fillers tend to settle out, especially since the viscosity of the components is reduced when they are heated to accelerate gelation. To overcome this, the filled polyols are continuously pumped from the mixing/storage tank through the lines to the mixing head and back. 

Tripoli. TripoH [1317-95-9] is a fine grained, porous, decomposed siHceous rock produced mainly in Arkansas, Illinois, and Oklahoma. It is widely used for polishing and buffing metals, lacquer finishing, and plated products. Since tripoH particles are rounded, not sharp, it has a mild abrasive action particularly suited for polishing. TripoH is also used in toothpastes, in jewelry polishing, and as filler in paints, plastics, and mbber. Rottenstone and amorphous siHca are similar to tripoH and find the same uses. In 1987 the abrasive use of tripoH in the United States totaled 26.6 million tons and was valued at about 3.1 million however, the portion used as a filler totaled 71.1 million tons and had a value of almost 10 million (4). 

In the calendering method, a PVC compound which contains plasticizers (qv) (60—120 phr), pigments (qv) (0—10 phr), fillers (qv) (20—60 phr), stabilizers (10—30 phr), and other additives, is kneaded with calender roUs at 150—200°C, followed by extmsion between clearance-adjusted roUs for bonding onto the substrate. This method is employed for products with thick PVC layers, ie, of 0.05—0.75 mm thickness. The main plasticizer used is di-2-ethylhexyl phthalate (DOP). For filler to reduce cost, calcium carbonate is mainly used. A woven or knit fabric made of cotton, rayon, nylon, polyester, and their blend fiber is used as substrate. For foamed vinyl-coated fabrics, the bonded materials are heated in an oven to decompose the foam-blowing... 

It is important to note that reinforced plastics remain a combination of materials differing in form or composition on a macro scale. The main constituents (resin, reinforcement, and filler) retain their identities and do not dissolve or merge into each other rather, they act in concert. These components can be physically identified and exhibit an interface between each other. 

Silica. The main uses of siUca are in the treads of off-the-road tines for improved chunking and tear resistance and as a component of the bonding system for brass and 2inc-plated steel cord. These are commonly used in radial passenger and tmck tire belt skim stock. In addition the body pHes of steel radial tmck tires, hoses and belts, and footwear use significant volumes of siUca as a reinforcing filler. 

Ester plasticizers are used mainly in very polar elastomers, such as neoprene and nitrile mbber, to improve low or high temperature performance or impart particular oil or solvent resistance to a compound 5—40 parts are commonly used (see Plasticizers). Resins and tars are added to impart tack, soften the compound, improve flow, and in some cases improve filler wetting out, as is the case with organic resins in mineral-filled SBR. Resinous substances are also used as processing agents for homogenizing elastomer blends. 

Calcium carbonate is one of the most common filler/extenders used in the paint and coatings industry. Consumer and contractor paint formulas can include products from submicrometer size to coarse mesh sizes. The main function of calcium carbonate in paint is as a low cost extender. It is also used to improve brightness, appHcation properties, stabiHty, and exposure resistance. Coarse products help to lower gloss and sheen or even provide textured finishes. The selection of product type and particle size is deterrnined by the desired performance and cost of the coating. 

Cyclohexene oxide [286-20-4] M 98.2, b 131-133 /atm, dj 0.971, n 1.452. Fractionated through an efficient column. The main impurity is probably H2O. Dry over MgS04, filler and distil several limes (b 129-134 /aim). The residue is sometimes hard to remove from the distilling flask. To avoid this difficulty, add a small amount of a mixture of ground NaCl and Celite (1 1) to help break the residue particularly if H2O is added. [Org Synth Coll Vol I 185 7945.]... 

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